Spark-plug.



F. E. WE-LKER.

SPARK PLUG.

APPLICATION FILED MN. 11. i917- Patented Dec. 11 ,1917.

4 mvmron FRANK E .WELKER":

momiiys mm: m WELKEB, F BEAVER; CREEK, MINNESOTA.

SPABK-PLUG.

Specfllca'tion of Letteralatent.

Patented Dec. 11, 1917.

I Application filed January 17, 1917. Serial No. 142,840.

To all whom it may concern:

Be it known that I, FRANK E. Warm, a citizen of the United States, and aresident of Beaver Creek, in the-county of Rock-and State otMinnesota,have invented certain new and useful Improvements in Spark- Plugs, ofwhich the following is a specification.

plugs, and has for its object to provide a" plug of the characterspecified, wherein the electrodes are so arranged and placed that" theywill be free from grease, soot and sediment, while at the same time theywill furnish' a spark of the character required to provide goodignition.

" In'the drawing is shown a sectional view of the improved plug.

In the present embodiment of the inven-,

tion a shell 1 is provided of metal',externally threaded at its onecylinder, and this shell is internally threaded to receive a plug 2 ofporcelain or other insulating materia the said plu entirely filling thecavity of the shell and held by the t reads.

' as shown, and this end is rounded and transversely notched or curvedas shown,

sleeve 7 the Within the material ran ed one of the electrodes 3, thesaid elect e bein grounded to the shell and to the engine. he plug 2 isof suflicient length to extend beyond the lower end of the shell and toform a spark chamber 4. The other electrode 5 is also embedded in' thematerial of the plug 2, and p the lower ends of the said electrodes areinto the chamber 4, and apart to form the spark p. v. At the upper endof the shell atapered opening 6 isprovided, and within this openthey arespaced ta ng is, arran d a tapering or conical insulatmg sleeve ofnncafl or the like, the said sleeve closely encirc the electrode 5.Within the plu the e ectrode 5 is offset laterally awa omth'e center,but at the electrode is at the center. The upper or small end of thesleeve 7 extends through the opening G and above the'shell as shown. Atapering sleeve 8 of porcelain invention is. an improvement in spark theelectrode are and for engaging 'the v of this plug is aris greater'thanthe exterior diameter of thesleeve 7 in order that there will be anannu(llar chamber 10 between the sleeves l7 an 8.

A washer 11 is arranged at the small end of the sleeve, and a nut 12 is,threaded onto the electrode where it extends beyond the washer 11. Thespark plug is completed by a cap 13 which 1s threadedupon the extendedend of the electrode above the nut 12. With theimproved spark lug, thepoints of protecte from grease, soot and sediment, being within thechamber 4,

while at the same time an eflicient s ark is provided insuring good iiti 12 and' the cap 13 are of conductin material topermit the connectionof the ead wire .with the electrode 5.

I claim:

1. A spark plug comprising a metal shell, a .plug of porcelain withinthe shell and extending below the same, the extended end being roundedand havin a transverse notch or recess electrodes em ded within theplugs'and extending into the notch or recess at-one end, one of theelectrodes enga the shell and the other'being insulated there-. from,said last named electrode extending above the shell, an insulatingsleeve between the electrode and the shell at the said extended end, athelastnaglllied d fh shu t en eupper en 0 t e e a nu thr e adeg ontothe el' trode above the last named shell, and electrode above the nut.

2. A spark plug com rising a metalshe an insulating plug wit tendingbelow the same, the extended end having a transverse notch or recess,and electrodes embedded within 'the plug and extending into the recess,said electrodes being spaced apart from the bottom of the notch.

sleeve'in spaced relation an ELMER vWlilLKILlz't.

e nut a cap threaded onto the.

the shell and ex-

